Dope or varnish for aircraft constructions



, vents. The rapidity with which the solvents UNITED srA gs PATENTXIKQFFICE.

SAMUEL Emvrsr (moves, or IELLING-ON-TYNE, se ms.

DOPE OR VARNISH FOB AIRCRAFT CONSTRUGTIONS. f

No Drawing.

have invented certain new and useful Improvements in Dopes or Varnishes for Aircraft Constructions, of which the following is a specification.

Dopes, varnishes or aircraft constructlon consist mainly of cellulose esters or ethers dissolved in volatile solevaporate creates difiiculty in the application of the do e or varnish to the surface to be coated. oreover, the coating does not sufficiently resist penetration of water.

Waxes have been added to cellulose ester varnishes with the result that the rate of evaporation of the volatile solvents has been retarded whereby it has been easier to apply the varnish. 1

By my invention a considerably better efiect in retarding evaporation is attained by using a mixture of waxes for the purpose in question, probably because as the waxes separate from the solvent in admixture with each other they remain longer in the plastic state than eitherof them separately would.

The proportion of wax may be varied within wide limits; as an example, it may be stated that for a celluloid dope in which the sol- Speciflcation of Letters Patent.

finishing materials for Patented Jan. 18,1921.

Application filed August 2, 1918. Serial No. 248,056. I

vent is a mixture of acetone or other ketone',

alcohol and benzole, the proportion of wax may equal that of the celluloid; for instance, if the latter is between 5 and 8 per cent. there may be added beeswax to constitute between 4 and 5 per cent. and paraflin wax to constitute between 2 and- 3 per cent. of the mixture.

Having thus described the nature of the said invention and the best means I know of carrying thesame into practical effect, I'

claim 1 v y 1. -A cellulose ester varnish containing a .mixture of waxes adapted to retard evaporation of the volatile solvent of the varnish I while the latter is being applied.

2. A cellulose ester varnish containing a mixture of beeswax andparafiin wax adapted to retard evaporation of the'volatile solvent of the varnish while the latter is being applied. r

-3. A cellulose ester varnish containing a mixture of beeswax and 'paraflin wax the quantity of which mixture is equal to the.

quantity of cellulose ester.

In testimony whereof I have signed my name to this specification in the presence of a subscrib' witness. v S L ERNEST GROVES.

Witness:

. C. S. Horxms. 

